How to add tooltip to menu item - c

Question

I'm looking for a solution to display a tooltip for a single menu item in my WinAPI program.
ID_MAIN_MENU MENU
BEGIN
...
END
MENUITEM "?", ID_RIGHT_BUTTON, HELP
END
I'm able to add tooltip for a control with TOOLINFO structure and TTM_ADDTOOL message, but this seems not apply to HMENU handle.
I found some C++ libraries that add tooltips to menu items, but I'm using C.
Moreover here it's not possible to use the WM_MENUSELECT message, which is sent only clicking on the menu, not hovering over.
An hypothetical image of what I want.
Any suggestion is appreciated.

Answer 1

Finally come to a solution good enough to make the tooltip appear on mouse over and disappear on mouse out (not perfect because has no initial nor autopop delay time).
#define _WIN32_IE 0x0300 // to reach TTM_TRACKACTIVATE in <commctrl.h>
#include <windows.h>
#include <commctrl.h>
HWND hToolTip;
TOOLINFO ti = {0};
// WndProc
case WM_CREATE: {
HMENU hmenu = CreateMenu();
AppendMenu( hmenu, MF_HELP, 123, "?" );
SetMenu( hWnd, hmenu );
hToolTip = CreateWindow( TOOLTIPS_CLASS, 0, WS_POPUP, CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT, hWnd, 0, 0, 0);
ti.cbSize = sizeof(TOOLINFO);
ti.hwnd = hWnd;
ti.uId = (UINT)hToolTip;
ti.lpszText = "My tooltip";
SendMessage( hToolTip, TTM_ADDTOOL, 0, (LPARAM)&ti );
break;
}
case WM_NCMOUSEMOVE: {
RECT rect;
GetMenuItemRect( hWnd, GetMenu(hWnd), 0, &rect );
// ^ zero-based position of the menu item
int x = LOWORD(lParam);
int y = HIWORD(lParam);
if ( x>=rect.left && y>=rect.top && x<rect.right && y<rect.bottom )
SendMessage( hToolTip, TTM_TRACKACTIVATE, TRUE, (LPARAM)&ti );
else
SendMessage( hToolTip, TTM_TRACKACTIVATE, FALSE, (LPARAM)&ti );
break;
}
case WM_MOUSEMOVE:
SendMessage( hToolTip, TTM_TRACKACTIVATE, FALSE, (LPARAM)&ti );
break;
Why I did use TTM_TRACKACTIVATE instead of TTM_POPUP?
Oddly TTM_POPUP is not defined in commctrl.h by MinGW (gcc 5.3.0).
TTM_POPUP needs Visual Styles enabled with manifest.
Eventually for me TTM_POPUP is ineffective in this scenario.

Answer 2

I distilled a simpler and more efficient solution to create a tooltip for a single menu item:
#include <windows.h>
#include <commctrl.h>
#define ID_BUTTON 123
HWND hToolTip;
TOOLINFO ti = {0};
// WndProc
case WM_CREATE: {
// create menu
HMENU hmenu = CreateMenu();
AppendMenu( hmenu, MF_HELP, ID_BUTTON, "?" );
SetMenu( hWnd, hmenu );
InitCommonControls(); // necessary in Windows XP to register TOOLTIPS_CLASS
// create tooltip
hToolTip = CreateWindow( TOOLTIPS_CLASS, 0, WS_POPUP, 0, 0, 0, 0, hWnd, 0, 0, 0 );
ti.cbSize = sizeof(TOOLINFO);
ti.uFlags = TTF_SUBCLASS;
ti.hwnd = hWnd; // main window handle
ti.uId = (UINT)ID_BUTTON; // distinguish it from eventual other tooltips
ti.lpszText = "My tooltip";
SendMessage(hToolTip, TTM_ADDTOOL, 0, (LPARAM)&ti);
break;
}
case WM_SIZE:
ti.uId = (UINT)ID_BUTTON;
// get new coordinates of item
GetMenuItemRect( hWnd, GetMenu(hWnd), 0, &ti.rect );
// ^ zero-based position of the menu item
// convert from screen to client coordinates
MapWindowPoints( NULL, hWnd, (LPPOINT)&ti.rect, 2 );
// ^ desktop handle ^ POINT structures that is one RECT
SendMessage(hToolTip, TTM_NEWTOOLRECT, 0, (LPARAM)&ti);
break;
I used InitCommonControls because is shorter and works, but is also obsolete and InitCommonControlsEx should be used instead.
Above code was tested also on Windows XP: it works, but GetLastError after CreateWindow returns a 1309 ERROR_NO_IMPERSONATION_TOKEN.
In order to solve it, create a manifest file and in resource (.rc) file add the line:
CREATEPROCESS_MANIFEST_RESOURCE_ID RT_MANIFEST "YourApp.exe.manifest"